Background documentationBacking Up to a Group of Parallel Data Carriers Locate this document in the navigation structure

 

To speed up the backup process, you can back up your data to several data carriers in parallel (subsequently called a group of parallel data carriers). Note that you cannot back up log entries to a group of parallel data carriers.

Most backup options are available for backups to a group of parallel data carriers as well: you can back up data to the local computer or to remote computers, you can use tape drives and you can connect third-party backup tools.

You combine backups to different types of data carriers. As the data is automatically distributed between the data carriers during the backup process, you can also combine carriers with different write speeds without difficulty.

The system stores the information on how many data carriers were used for the backup on the data carrier that was finished last. All other data carriers only contain details of the successful write process of the backup data.

A parallel backup is not fundamentally different from a sequential backup: During sequential backup, you specify the backup template at the start of the backup operation. As soon as the defined data carrier is full, you will be asked by the system to enter the next backup template or an operating system path (including the name of the file or pipe) where the next data carrier can be accessed. Parallel backup runs similarly to this, but takes place on several data carriers simultaneously. The system requests a new data carrier for the first carrier that is full, and proceeds accordingly for each individual data carrier until the data is completely backed up. Therefore, a parallel backup is normally a combination of parallel and sequential backup operations that takes place when the number of write-to data carriers exceeds the number of parallel data carriers.

Example Example

For your backup, you need the storage space of 7 tapes. If you carry out this backup with 5 tape drives, then 5 tapes are written simultaneously at first (parallel backup). The first tape drive with a full tape requests a new tape. Data is then backed up to the sixth tape sequentially. All other tape drives continue simultaneously (parallel backup) until another tape drive is full. This drive then requests a new tape (number 7).

End of the example.

If the system requests the next data carrier, you must confirm this in order to continue and complete the backup operation.

  • Insert the next data carrier.

  • Enter the command to only write to the other data carriers.

  • If Database Manager CLI is used, then you can specify the AUTOIGNORE option at the start of the backup process. This allows the system to continue writing to the other data carriers without asking for confirmation.

    Caution Caution

    Only use this option when you are sure that the complete amount of backup data will fit on the first set of data carriers in the group (no succeeding data carriers are required).

    End of the caution.

    You can simplify background backups in Database Manager CLI using the AUTOIGNORE option.

    Example Example

    You schedule regular nightly data backups for your system. The memory of 5 tapes is required for your backup. You start the backup process in the evening and enter the AUTOIGNORE option. If you carry out a backup with 5 tape drives, then 5 tapes are written simultaneously at first (parallel backup). The first tape drive with a full tape stops the backup process. All other tape drives continue until all the data is backed up.

    End of the example.

Prerequisites

Procedure

Use the normal functions for data backup.

More information: Backing Up Data

Result

You now have a data backup consisting of several data carriers. You can import this backup sequentially or in parallel to the database. For example, this can be used to restore the data after a database error.